Off-state gate leakage current in N-channel MOSFETs with gate dielectrics prepared by different techniques

The off-state gate current of n-channel MOSFETs with OX, RONO, N20N, and N20G oxides as gate dielectrics was investigated in this work. It is revealed that gate current conduction mechanism in the low field region is very different for these oxides. Enhanced conductivity is observed in RONO and N20G oxides, which is attributed to the trap-assisted tunneling mechanism. Therefore, in view of gate leakage, the method of nitridizing pre-grown thermal oxide is more feasible than directly growing oxide in N2O ambient, especially in leakage sensitive applications, such as very-low-power battery-based circuits, DRAM cells, etc.published_or_final_versio